The idea seemed to be that younger people who're more "open minded" about abstract concepts "got it" more and the article even suggests that younger viewers, and games, "get" the "levels" aspects and such more. Older viewers, perhaps a bit more rigid in the philosophy views and less prone to more abstract thoughts and ideas were less likely to get it.
I think it's more like, younger people haven't seen a whole lot of movies that cover the same ground, so they tend to be easily impressed and conned into thinking a film is profound or mind-blowing, when it's really just a well executed popcorn flick that deals with concepts handled better elsewhere. When I watched Inception, I saw a lot of echoes of other movies like The Matrix, Eternal Sunshine of the Spotless Mind, The Waking Life, and to me it didn't really top any of those films.
Also, as someone who's 35, your poll makes no sense. How should I choose between "35 or younger - Neutral to the movie" and "35 or older - Netural [sic] to the movie"?